Modeling Considerations for Ingestion Pathway Dose Calculations Using CAP88

Area of Science:

• Environmental Science
• Radiation Protection
• Risk Assessment

Background:

• The U.S. Environmental Protection Agency developed the CAP88-PC computer model.
• Compliance with National Emission Standards for Hazardous Air Pollutants (NESHAPS) is demonstrated using this model.
• The model integrates atmospheric transport and terrestrial food chain models.

Purpose of the Study:

• To compute radionuclide concentrations in air, on surfaces, and in food.
• To estimate radiation doses to individuals near radionuclide-emitting facilities.
• To illustrate the impact of input parameters on ingestion dose calculations.

Main Methods:

• Utilizes U.S. Nuclear Regulatory Commission Regulatory Guide 1.109 food chain models.
• Combines atmospheric transport with food chain modeling.
• Allows user selection of assessment area size and receptor locations.

Main Results:

• Radionuclide concentrations are calculated in various environmental media and food products.
• Annual effective dose from ingestion is estimated for exposed populations.
• The choice of assessment area size and receptor locations influences calculated ingestion doses.

Conclusions:

• Understanding CAP88-PC model mechanics is crucial for accurate dose assessment.
• Differentiating between "Population" and "Individual" run types improves ingestion dose modeling.
• Proper parameter selection enhances the reliability of environmental radiation dose estimations.